Patent reference 1 describes that (i) a compound represented by the formula:
wherein R is an aliphatic hydrocarbon group optionally having substituent(s), an aromatic hydrocarbon group optionally having substituent(s), a heterocyclic group optionally having substituent(s), a group represented by the formula: —OR1 (wherein R1 is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s)), or a group represented by the formula:
wherein R1b is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s), and R1c is the same as or different from R1b and is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s),R0 is a hydrogen atom or an aliphatic hydrocarbon group, or R1 and R0 form a bond with each other,ring A is a cycloalkene substituted by 1 to 4 substituents selected from (1) an aliphatic hydrocarbon group optionally having substituent(s), (2) an aromatic hydrocarbon group optionally having substituent(s), (3) a group represented by the formula: —OR11 (wherein R11 is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s)) and (4) a halogen atom,Ar is an aromatic hydrocarbon group optionally having substituent(s),a group represented by the formula:
is a group represented by the formula:
and n is an integer of 1 to 4, and(ii) a compound represented by the formula:
wherein Ra is an aliphatic hydrocarbon group optionally having substituent(s), an aromatic hydrocarbon group optionally having substituent(s), a heterocyclic group optionally having substituent(s), a group represented by the formula: —OR1a (wherein R1a is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s)) or a group represented by the formula:
wherein R4a and R5a are the same or different and each is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s),R0a is a hydrogen atom or an aliphatic hydrocarbon group, or Ra and R0a form a bond with each other,Ara is an aromatic hydrocarbon group optionally having substituent (s),a group represented by the formula:
is a group represented by the formula:
and n is an integer of 1 to 4, a salt thereof and a prodrug thereof; andpatent reference 2 describes that a compound represented by the formula:
wherein R1 is an aliphatic hydrocarbon group optionally having substituent(s), an aromatic hydrocarbon group optionally having substituent(s), a heterocyclic group optionally having substituent(s), a group represented by the formula: —OR1a (wherein R1a is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s)) or a group represented by the formula:
wherein R1b and R1c are the same or different and each is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s),X is a methylene group, NH, a sulfur atom or an oxygen atom,Y is a methylene group optionally having substituent(s) or NH optionally having substituent(s),ring A is a 5- to 8-membered ring optionally having 1 to 4 substituents selected from the group consisting of (1) an aliphatic hydrocarbon group optionally having substituent(s),(2) an aromatic hydrocarbon group optionally having substituent(s), (3) a group represented by the formula: —OR2 (wherein R2 is a hydrogen atom or an aliphatic hydrocarbon group optionally having substituent(s)) and (4) a halogen atom, Ar is an aromatic hydrocarbon group optionally having substituent(s),a group represented by the formula:
is a group represented by the formula:
m is an integer of 0 to 2,n is an integer of 1 to 3, andthe total of m and n is not more than 4;provided that when X is a methylene group, Y is a methylene group optionally having substituent(s), a salt thereof and a prodrug thereof have a nitric oxide (NO) production-inhibitory effect and an inhibitory effect on the production of inflammatory cytokines, such as TNF-α, IL-1, IL-6 and the like, and are useful as agents for the prophylaxis or treatment of diseases including cardiac diseases, autoimmune diseases, inflammatory diseases, central nervous system diseases, infectious diseases, sepsis, septic shock and the like.
Patent reference 3 describes that the above-mentioned compounds are useful as TLR signal inhibitors or agents for the prophylaxis or treatment of severe sepsis.    patent reference 1: WO99/46242    patent reference 2: WO01/10826    patent reference 3: WO03/84527